Adhesive for magnetic cores formed of magnetic layers



LAYERS H. VOGT Aug. 2o, 193".

ADHESIVE FOR MAGNETIC CORES FORMED OF MAGNETI Filed Feb.

Sin/'n Zhu/Zena mais i, a was 2,011,698

UNITED STATES. PATENT ori-ICE ADHESIVE FOB MAGNETIC CORES FORMED F MAGNETIC LAYEBS Bans Volt. Berlin-Dahlem, Germany Application February 5, 1934,8erial No. 700,840 ln Germany June 1, 1933 T'his invention relates to an improvement in It is not necessary to use heat for Iiolning the magnetic material comprisingaplurality of lamllaminas, although it may be useful in special ne, each formed of an insulating sheet coated cases to use heat additionally. with magnetic particles, said lamina; being united The magnetic cores are built up from superby an adhesive. Such laminated magnetic mateposed stampings cut ;from these plates, said s rial is specially used for making magnetic cores stampings again being united by pressing. The for high frequency coils, as referred to in my tenuous layer of the adhesive, present on the surprior application, Serial No. 637,156, tiled Octoface of each stamping, will cause the stampings ber 10, 1932. to adhere to each other without appLying heat l0 It is an object of my present invention to imor an additional adhesive. 10

prove the mechanical and heat stability of said I claim:- laminated magnetic material and to facilitate l. A magnetic material comprising a plurality the working, more particularly the stamping, of of lamine, each comprising an insulating sheet same. coated with magnetic particl, said laminebei Another object of the invention is to facilitate ins united by a solid chlorinated hydrocarbon u the Joining of the superposed magnetic layers. having a melting point between 90 and 140 C.

According to this invention the magnetic ma- 2. A magnetic material comprising a plurality terial comprises a plurality of lamin, each of laminas, each comprising an insulating sheet formed of an insulating sheet coated with magcoated with magnetic particles, said lamine benetic particles, said lamine being united by a ing united by a solid chlorinated naphthalene, zu

solid chlorinated hydrocarbon having a melting which is liquid in hot state. point between 90 andfl40" C. 3. A magnetic material comprising a plurality The drawing shows greatly enlarged a partial of lamine, each formed of an insulating sheet cross section of a magnetic core constructed in coated with magnetic particles mixed with an accordance with my invention. insulating binder, said lamine being united by Each lamina comprises an insulating sheet I a solid chlorinated naphthalene, which is liquid which is coated with a magnetic layer, comin hot state. prising magnetic particles 2 and an insulating 4. A magnetic core comprising a. plurality of binder l. A plurality of said lamine are united lamine, each formed of an insulating sheet coated by the adhesive 4, consisting of a solid chloriwith magnetic particles, mixed with an insuso nated hydrocarbon, more particularly of a solid lating binder, said lamine being united by a solid chlorinated naphthalene, having a melting point chlorinated naphthalene, which is liquid in hot between 90 and 140 C. state.

In the practice of my invention I pass said 5. A method for joining core lamine of maglaminas, comprising a long strip of insulating netic powder cores, made of insulating sheets as sheet I, such as paper, and a composite coating coated on both sides with a la'yer of magnetic of magnetic material 2 and an insulating binder particles, comprising coating said lamine with 3 on both sides of said insulating sheet I. through solid chlorinated naphthalenes which are liquid a heated bath of said chlorinated solid naphin hot state and joining said coated lamine un- 40 thalenes thus obtaining a tenuous layer 4 of der pressure. 0' said naphthalene on both sides of said lamine. 6. A method of forming magnetic core elements A plurality of lamine, which are so prepared, for high frequency use, which comprises applyare then united under pressure. Due to the paring a thin film of liquid chlorinated naphthalenes, ticular crystal structure of such adhesives, and which are solid at normal temperatures, to the their consequent high elasticity and toughness, surface of core lamine made of insulating sheet 45 the tenuous layers thereof will cause the lamina: coated with magnetic particles in an insulating to adhere to each other very tightly so that binder, uniting a plurality of such coated'larnivery solid plates are obtained, which will not n under pressure to obtain a firmly united lamitend to separate into the individual layers, as nated plate, and stamping out the core elements will often occur when using other adhesives. The from said laminated plate.

plates so obtained may be stamped like sheet HANS VOGT. metal, producing no waste. 

